This version adds the feature to toggle the selections for all currently displayed items.Note: this really means the displayed items, not necessarily all items in the current collection - items which are on other "pages" of the collection are not affected.

In addition, I also built in a nice little easter egg

Spoiler:

No, I'm not going to tell you what it is. After all, that's what easter eggs are all about. It's not terribly hard to find though, either by accident, or by looking at the changeset. I hope you enjoy it if you find it. But please don't spoil the fun by openly discussing it here or disclosing it to others.